ERROR in iTunes while trying to update to ISO 5 on 3GS 6.15 oldbootroom

[aemosh]

I tried using 2 methods but both failed with the message
" The iPhone could not be restored. This device isn't eligible for the requested build"

1st. The normal update and restore using iTunes. Failed with error but no error code written.

2nd. Using redsn0w to own my 3gs into DFU mode then click option-restore on iTunes on a firmware I created myself with redsn0w. Failed with error but no error code written.

My iPhone 3gs is running on iPad baseband. How can I successfully update it to IOS 5? Any idea?

Thanks for you help

[805 93003]

Just to be certain everything is right.

Download TinyUmbrella, launch, go to Advanced Tab and make sure Box with Set Hosts to Cydia on Exit is empty (no check mark). Exit TinyUmbrella.

Download new version of Redsn0w, I think they were updated yesterday. Make a new custom firmware with Redsn0w for ios5.

Use Redsn0w to put iPhone into Pwned DFU Mode.

Restore iPhone with Custom Firmware with iTunes 10.5.